Demonstrators prepared Monday to launch another day of major protests in Chicago as world leaders met at the NATO summit, while commuters heading into the city found themselves navigating extra security and revised train and bus routes designed to dodge the summit zone.

Many downtown businesses told their employees to stay home during the second and final day of the summit — where world leaders are discussing the war in Afghanistan, European missile defense and other security issues — because of traffic snarls and the possibility of more protests.

The weekend's protests drew thousands and called attention to everything from foreign policy to the economy, but were mainly peaceful. The biggest conflict came late Sunday, when a group of protesters clashed with police at the end of a march.

On Monday, a group of demonstrators with the Occupy Chicago movement were planning to protest outside of Boeing Corp.'s headquarters. Officers were stationed there ahead of time Monday morning, and an orange barricade blocked off the building's entrances. Occupy claims the multi-billion-dollar aerospace company avoids paying taxes because it produces airplanes for the U.S. military.